1. Technical Field
One or more embodiments of the present invention relate to microphones, and specifically, to a microphone in which a microphone chip (acoustic sensor) is accommodated in a package.
2. Related Art
For example, U.S. Pat. No. 7,166,910 describes a MEMS (Micro Electro Mechanical Systems) microphone manufactured using the MEMS technique. In the microphone described in FIG. 1 of U.S. Pat. No. 7,166,910, a package is configured by a substrate and a cover, a microphone chip and a circuit element are arranged side by side on an upper surface of the substrate, and an acoustic perforation is opened in the cover. Furthermore, in the microphone described in FIG. 31 of U.S. Pat. No. 7,166,910, the microphone chip and the circuit element are arranged side by side on the upper surface of the substrate, and the acoustic perforation is opened in the substrate at the lower surface of the microphone chip. Moreover, in the microphone described in FIG. 32 of U.S. Pat. No. 7,166,910, the microphone chip and the circuit element are arranged side by side on the upper surface of the substrate, and the acoustic perforation is opened in the substrate at a position deviated from the microphone chip.
Miniaturization is demanded on electronic devices particularly portable devices, and to this end, components such as a microphone need to be mounted at high density on a small circuit substrate. However, in all the MEMS microphones described in U.S. Pat. No. 7,166,910, it is difficult to miniaturize the microphone and in particular, it is difficult to reduce the occupying area at the time of mounting (hereinafter referred to as the mounting area) because the microphone chip and the circuit element are arranged side by side on the upper surface of the substrate or the lower surface of the cover.
It is effective to miniaturize the microphone chip and the circuit element themselves in order to miniaturize the microphone, but the sensitivity lowers if the microphone chip is miniaturized. Therefore, it is desired to reduce the dimension while maintaining the properties and to reduce the mounting area in the microphone, but these are difficult in conventional microphones.